The Truth Stings
by Aria6
Summary: Fate/Zero fic! What if Kiritsugu failed to destroy Kayneth's mage circuits due to the fortuitous intervention of Lancer? Things take an interesting turn when mana transfer is required... Kayneth/Diarmuid, alternate events
1. Chapter 1

Author's Note: This is just sort of a 'what if'. What if Kayneth's magic circuits weren't destroyed and what if he weren't such a dick. ^_^

* * *

"Damn it damn it damn it." Kayneth chanted softly to himself as he tried desperately to save his servant. And the night had started so well, too. How had it all gone so wrong?

Grimly, he made a vow never to underestimate his enemies again as he applied his magic to Lancer. If he hadn't intercepted that bullet… Kayneth had sensed the spell in it and realized, with pure horror, what it would have done to him. Nothing was more precious than his magic and Kiritsugu had tried to take that away from him. And how close he came! For once, he blessed his idiot Servant. The fool had taken that bullet for him.

However, his core was pierced and he was bleeding out. They'd gotten him back to base with plenty of healing enchantments, but all the movement had made things worse. Kayneth grit his teeth as he fought to heal the man and realized it just wasn't working. Diarmuid's breathing was slowing and he could feel his skin cooling as he continued to hemorrhage blood and mana. There was only one option left.

"Sola-Ui, get me your hand cream." He snapped and she stared at him wide eyes. Idiot! "NOW!" She was going to argue, he could see that, but he fixed her with a stare of helpless rage and the damned woman finally got the message. She vanished to get him that and he looked down at Lancer, hesitating a moment. "Lancer, can you hear me?" He didn't have high hopes. No response. "Diarmuid, by my command spell, if you can listen and respond you will do so." He hated to use it for this but by damnation he had no choice. Eyelids fluttered and opened, dull gold eyes moving to look at him. "I need to transfer mana to you but I will not do this without consent. Do you wish me to do so? You'll die if I don't." Kayneth warned. Diarmuid seemed to think about it for a moment.

"Do… it." He finally rasped before closing his eyes again. Kayneth hoped that meant he'd passed out. It would likely be easier for him. This wasn't going to be pleasant for such a man, he was sure. He held out his hand and Sola-Ui passed him the hand cream, along with an objection.

"Kayneth, I'm the one feeding him power. I could do that." She said and he was sure she'd love to. Honestly, he'd rather he let her! Unfortunately it wouldn't work.

"No you couldn't. Look at him, he couldn't sustain an erection long enough for you to take him." Kayneth snapped even as he began disrobing the man. Too much clothing – oh curse it. A quick spell and he snapped through the leather, tearing it away. "Once I get some energy into him we can fix that – " Mutual orgasm was necessary for the full transfer. "But right now you couldn't even start. Now get out, I have to do this." He sensed her defeat as she realized he was right. Quickly slathering his hand in cream, he began to spread the man's cheeks. Oh curse it there was really no time for this! Keeping a very close eye on the mana Lancer was losing, Kayneth did his best to prepare him.

Thankfully, it wasn't hard to sustain his own erection. He swallowed a little at the thought of burying his cock in the other man. His lifelong curse had been his lack of desire for women and the thought of taking a man as handsome as Diarmuid… oh, it was titillating. However, the lack of time was another curse and Kayneth grimaced as he realized the mana hemorrhage was ebbing because there was almost no mana left to go. He had to take the man NOW, inadequate stretching or not. Taking a deep breath, he yanked down his pants and slathered his cock in cream before grasping Lancer's hips and taking him in one smooth, quick jerk. Diarmuid made an odd little whining sound and Kayneth hoped he wouldn't remember that.

"Sorry." He muttered, knowing the man had to be in pain. Regrettable that he was still slightly conscious, if the flickering of his eyelids was any indication. As gently as he could, in the circumstances, he began to take his Servant. Every thrust let him infuse a bit of mana into him, and in a way that was far more intimate than the healing spells. This was truly the only way to staunch the breakage of his core and Kayneth relaxed a little inside as he realized it was working. It would have been terrible to do this to Diarmuid to no purpose. "That's better…" He crooned in his ear, feeling that incredible tightness around his member. He hadn't really been paying much attention before but now that he knew it was working he was noticing how _good_ it felt. "Mmm…" Reaching beneath the man he began stroking his flaccid cock, trying to work him up. As he did he tried to adjust himself, find his prostate. If they couldn't achieve mutual orgasm this would be far less efficient than it could be…

He knew when he'd found it. He felt the jerk of Diarmuid's body, the way the man pressed back against him for a moment. He also felt the stiffening of the cock in his grasp and that helped him with his task, making his strokes easier. Kayneth rested a kiss on Lancer's still-clothed shoulder even as he reminded himself that this was just mana transfer. They were not making love, they were merely… transferring mana. That it felt wonderful was immaterial. Perhaps even a little shameful… well, extremely shameful…

He didn't really feel that, though. What he felt was the joy in finally expressing his true nature, the long hidden desires for his own sex. The fact that Diarmuid was such a beautiful man made it better. Unfortunately, he was waking up as his spiritual core continued to heal.

"Maaa… ster…" That gasped out word made his cock even harder, if possible. Kayneth restrained himself from taking the man faster, carefully hitting his prostate again. A sweet little whimper and that rod in his hand leaking a bit were a sign of his efforts.

"Shhh. We're almost done." He soothed his Servant, squeezing his penis and making him gasp again. "Just a little more…" It would be better to get it done with quickly, as wonderful as it felt. The Irish were not noted for their regard for this sort of thing. But then, was anyone, aside from the ancient Greeks? Rider and Archer were about the only ones who came from times when it was remotely accepted… at least, if he'd read the legends of Enkidu right…

Resolving to never mention that to Archer – there were less painful ways to commit suicide if he was wrong – he speeded his strokes, matching them with his thrusts against Diarmuid's prostate. He felt the sharp pulse of that member in his hand, heard the gasp as his Servant took pleasure. Velvety walls clamped down on him and Kayneth gasped as his own orgasm came over him. He stared at jet black hair as his body shook with the force of it, filling his Servant with precious mana. To his pleasure, he saw even a few minor cuts and nicks heal.

"Excellent." A quick check confirmed what he'd seen… Lancer was completely replenished. Diarmuid made a sound of discomfort and he blinked. "Ah. My apologies…" He quickly untangled their bodies before regarding the other man with concern. He was slumped on the bedsheets, his body extremely dirty and his clothing – which was only spiritual, he could bring it back now – in shreds. Between the blood and cum he desperately needed a bath but Kayneth suspected he couldn't move. Snapping his fingers, he summoned a wind-based servant. Not only was he above man-handling his Servant, but he was afraid Diarmuid might be too heavy for him.

"Lift him up, carefully." He instructed the servant and Diarmuid slumped as he was lifted off the bed. "Bring him to the bathroom." Once he had Lancer settled in the tub, he instructed the wind servant on how to clean him. Sadly, such things really weren't bright enough to be trusted such tasks on their own. He augmented it with a little water sprite and soon his half-conscious Servant was covered in bubbles. Vaguely, Kayneth thought he should have been recovering faster than this. His mana was completely replenished… but Diarmuid had taken a shock to all his senses.

Hopefully he would be better by tomorrow.

* * *

The next day, things were a touch awkward.

Sola-Ui was quietly furious at them both. Quietly, because she did understand that his actions had been the only way to save Diarmuid's life. Kayneth wished he could think her fury was over his infidelity, but he was wearily certain it was because he'd been the one to experience the Servant's body and not her. That damned beauty spot was destroying her mind.

He tried to distract himself from Sola-Ui's growing instability by enjoying his fortress. He had all the money in the world but the truth was, he rarely lived in such luxury. The clock tower wasn't noted for it and he didn't spend a lot of time on his estates. Vaguely he thought he should be concentrating, plotting out his next move, but last night had been a bit of a shock. Dying in such a manner or worse, surviving with his mage circuits destroyed… Kayneth shuddered internally.

 _Master, are you well?_ Lancer's voice sounded very tentative and Kayneth sighed.

"I'm fine." That was the other thing that was awkward. Diarmuid was behaving extremely oddly. Well, that was to be expected. No doubt he'd just lost his anal virginity, and to his own Master. And their relationship as Servant and Master had… changed. Kayneth couldn't quite see him the same way anymore, as a tool to be used for his goal. The man had taken a bullet for him! Admittedly that was what a Servant was for but that had been no ordinary bullet. He couldn't help but feel intensely grateful and that was adding to their difficulties. They were both dancing tentatively around each other, it seemed. "I think I'll have a bath." Something to soothe his nerves and clear his mind. "Don't bother me unless the building is on fire."

 _Yes Master._ Diarmuid sounded distressed and Kayneth grimaced as he rubbed his forehead. What was the man on about? Aside from the obvious? Sighing, he went to take his bath. What a marvelous tub! Easily big enough for two people. For just a moment, he remembered how his Servant had looked, covered in suds and semi-conscious. It had been, well, cute…

Taking a deep breath, Kayneth began to run the water. He needed to banish those images. It wasn't happening again, unless they managed to get themselves in another awful fix. That made him frown. He didn't want something like that to happen again.

He added the bubble bath to the mix, smiling as the bubbles began to bloom. Sola-Ui was a bit disdainful about it, but he loved bubble baths. They reminded him of so many happy childhood memories, time spent with his mother.

Settling in for a long soak, he closed his eyes and let his mind empty out. All the cares and worries… the doubts that were starting to gnaw at him… he let them all go. Just enjoying the peace and quiet that was a really great bubble bath. Ah, it felt wonderful…

Kayneth was starting to get pruny when he finally pulled himself out of the water. A quick dry and a robe to cover his nakedness and he was feeling much, much better. Humming softly to himself, he left the bathroom to get dressed. What should he wear? Something for lounging around. Not really caring, he picked out a pair of brown slacks and a matching vest. It was good clothing, yet also very comfortable. The best of both worlds.

Grabbing a bottle of wine and a book, he went one of the many rooms at his disposal and settled in for a good read. This particular room had a beautiful view, an entire wall was nothing but window, giving him a gorgeous city panorama. Eventually, he set his book aside and just sipped his wine, looking out at the lights. It was –

"Master?" He managed to control his start of surprise and gave Diarmuid a sharp look. The harsh words he'd been about to say died as he saw the man kneeling beside the sofa, his head bowed subserviently.

"Stop that." He said irritably. It seemed particularly graceless, after the man had saved his life. His Servant looked up, confused by the admonition. "What is it?" He tried to gentle his tone a bit. Diarmuid seemed almost ready to jump out of his skin.

"I… Master, please, can we talk about this?" There was nothing he less wanted to do but Lancer was radiating nerves. It would be cruel to leave him in such a state. Had the man been working himself up all day? Kayneth sighed before gesturing to the chair to his right.

"Have a seat." He said and Diarmuid came to his feet before settling into the chair. Kayneth struggled not to notice how easily he moved, the grace he naturally carried. "What do you want to talk about?" What had happened between them, obviously. But what needed to be said? It was a mana transfer. Diarmuid looked at the ground, his expression tired and sad.

"I'm sorry, Master. My… ineptitude forced you to do something you did not want to do." Kayneth stared at him for a moment, unable to believe what he was hearing. Lancer was blaming himself for this? "And your fiancée is most upset." Well, that was true.

"She's a harpy." He growled and Diarmuid looked at him in surprise. Well, this was the first time he'd betrayed his true feelings to the man. "I try to act like I love her in hope that the emotion will come." He knew that could actually work. It was a psychological trick. Just smile! How inane it sounded but forcing a smile could actually improve one's mood. Unfortunately… "It's not working because she's a damned harpy." Kayneth knew the disdain Sola-Ui held for him. And contempt as the worst emotion to see in one's spouse. "Hrmph." He drained his wine glass before reaching for the bottle and pouring himself another. Diarmuid was looking almost stricken.

"Master, I'm sure that is not true. It's only your frustration over my cursed visage." He said and Kayneth sighed. He wished it was but he knew better. "And I truly, deeply regret that you were forced to… soil yourself with my body." …Erm… Well, that was an interesting take on the situation.

"Please, stop apologizing for that." He took a deep drink of the wine, wishing it was something harder. Diarmuid had no idea what he'd actually felt and it was a bit maddening. "That demonic bullet would have killed me if you hadn't intercepted it." Didn't he understand that? His Servant looked puzzled.

"I could have allowed you to block it yourself. The mercury you use is amazingly efficient. I acted without thinking." He said humbly and Kayneth almost choked on his wine.

"You don't know…?!" Of course he didn't. He wasn't a magus. "Diarmuid, if that bullet had hit my defenses I would almost certainly be dead now. It was designed to disrupt mage circuits." He wasn't entirely certain how it worked, but he'd sensed the intention behind it when it had gone off on Lancer. "Fortunately, as a Heroic Spirit you're less vulnerable. I, on the other hand, would have suffered immensely." He took another mouthful of wine, a bit more slowly this time. It was too fine a vintage to waste. "You have served me very well and I am grateful to you for your sacrifice." From the widening of his golden eyes, Diarmuid hadn't been expecting that.

"Thank you, My Lord." He sounded overwhelmed by the praise. Well, he hadn't been dishing out a lot of that. But this time, Lancer had earned it. "Still, does it trouble you?" Ah, that business.

"Mmm, no. To tell the truth, it doesn't." For a moment he almost stopped himself but then again… why? Diarmuid was his servant and he'd never come clean about this in his whole life. Why not now? "I am attracted to men." He said candidly and saw Lancer's eyes go wide. "No doubt another reason my fiancée is such a harpy." Did Sola-Ui sense that she wasn't desired? Perhaps.

"Oh. I had no idea." Diarmuid's voice sounded muted and Kayneth hoped the man wasn't going to be even more unnerved by the revelation. Theoretically, he could order his Servant to have sex with him. He never would – he had a few standards – but still. "If that is so, why are you to be wed?" He asked after a moment and Kayneth gazed into his wine for a moment, seeing his reflection in the dark red surface.

"Being a magus of ancient and impeccable breeding has obligations as well as privileges." He finally said. Something that damned Waver couldn't see. But as an outsider looking in, it had to be hard to see all the downsides of power. "Mainly, the duty to pass the bloodline on. My marriage was arranged between my father and Sola-Ui's." Another reason for Sola-Ui to despise him, if she'd needed one. Although… "We didn't object to it." On his side, there'd seemed like no point. Kayneth imagined she'd felt much the same. They were fated to marry someone based on breeding and power so what did it matter who they picked?

"My master's marriage to Grainne was also arranged." Diarmuid said after a moment and Kayneth nodded. He'd researched his hero, of course, although he strongly suspected much of the legend was balderdash. People so loved to embroider. "I often think that's how she fell to my curse so easily." He sounded saddened by it. "It bothers me, how much fate seems to be repeating itself." Kayneth finished his glass of wine and frowned as he looked at the bottle. It was empty?

"Well, I won't go chasing you with an army, if it's any consolation." He said, before standing. Or rather, trying to. It felt like all the wine suddenly went to his head and he stumbled against the coffee table, a sharp pain going up his leg.

"Master!" Warm arms were suddenly there, steadying him, and Kayneth blinked. Lancer was there, close enough to kiss. His breath came short as he looked into that beautiful face (not unnaturally so, though, as a man he was immune to the love spot) and felt the desire to do it.

He didn't though. It was Diarmuid who slid a hand through his hair and pressed their lips together. The kiss was shockingly gentle from such a powerful warrior, and also wonderfully intimate. Kayneth allowed himself to savor it, feeling protected by the strength that was his Servant. The body against him was so strong and desirable and he tangled his fingers in leather, feeling the pulse of prana in the man against him…

It was the sound, almost like a teakettle about to boil over, that broke the moment. They both looked, startled, and Kayneth blinked as he saw Sola-Ui. She'd been pushing a little cart loaded with covered plates and her face was darkening with rage. With a sinking feeling, Kayneth was sure he knew where those plates were about to go.

"YOU – " And the first plate flew through the air. He managed to duck but Diarmuid wasn't so lucky, his leathers suddenly getting splattered with sauce as a piece of meat hit him in the arm. Kayneth vaguely listened to Sola-Ui's shrieks, hiding behind the couch as she continued to throw things at them both. Oh, she was going to go to her father, tell him all about this and ask for an annulment to the engagement? And tell everyone else in the clock tower about his perversions? Oh, and now she was starting on Diarmuid, how she should have known he was a pervert since he didn't want her and the whole story of Grainne was probably a romantic lie and he'd really had sex with Fionne… fortunately her shrieks were so difficult to decipher that Diarmuid was just looking panicked and confused as he followed his master's lead and took cover. Kayneth was only managing to understand from long practice and that was rather sad, wasn't it?

Finally she stormed out, yelling that she was never coming back and he could take care of his own stupid Servant since he liked him so much. Kayneth waited until he could no longer hear the stomping before straightening and looking around.

"Oh dear." The room was an absolute mess. Sighing, he summoned his mercery as well as a few other elemental servants to clean it all up. "I think… ah, yes." The overturned cart had napkins. Fishing a few out, he handed them to Diarmuid, who used them to dry himself with a downcast expression. "Has she left the building?" He asked and his Servant hesitated before briefly going immaterial and checking. A moment later, he rematerialized.

"She has left, My Lord. I'm terribly sorry about this." Diarmuid apologized and Kayneth sighed before waving it off.

"Don't be. I'm glad to be rid of the baggage although the damage to my reputation…" From the grim look on his face, his Servant understood that perfectly. Well, of course he would. What would have happened to a Knight of Fianna caught at such a thing? Did he even want to know? "Mmm. Could you fetch another bottle of wine? And two glasses?" The ones from the cart were shattered. "And meet me in the drawing room." That was the room he'd turned into his study, filled with all kinds of books. "I think we both need to relax."

"Yes, My Lord." The way Diarmuid looked at him for just a moment, the heat in those golden eyes, almost turned his knees to water. His Servant really desired him? That was more than he'd ever hoped for! Repairing to the drawing room, Kayneth took a seat and thought about recent events. He would have to switch Lancer over to drawing from his mana as soon as possible, before Sola-Ui could cut him off. Ah, that would lower his reserves significantly. His stamina in mage combat would be cut in half, roughly. And Sola-Ui herself had been a potent ally, capable with destructive magic. Really, losing her was an enormous setback to his plans. Yet, he couldn't seem to regret it.

In fact, Kayneth found that he was feeling happier than he had in years.


	2. Love and War

Kayneth spent the next week in a love nest with his Servant.

Vaguely, he knew it was absurd. He should be plotting the demise of the other participants in the contest. He should be forging alliances and planning some good backstabbings. Yet, Kayneth couldn't tear himself away from Diarmuid. It wasn't just his incredible beauty, either. It was the fact that they were actually talking _to_ each other now rather than _at_ each other. A critical difference.

Oddly enough, or perhaps not, their most intimate conversations usually happened after sex.

"I feel like you've done this before," Kayneth observed as he luxuriated in the afterglow, gently running his fingers over Diarmuid's chest. Lancer had taken him this time. At first the man had been hesitant but Kayneth had wanted to be dominated, and Diarmuid had quickly warmed to the task. He felt the man beneath his hand stiffen a little. "Diarmuid?" Gazing into the other man's face, he saw a ghost of pain in his visage.

"When I was very young there was a good friend… we meant a great deal to each other and experimented together, although we knew it was forbidden," Diarmuid admitted in a low tone. "Unfortunately, he died in his first battle." …Ah. Kayneth felt a chill at the thought and it brought back the memories of Kiritsugu's bullet. Was he unnerved by that? Yes, absolutely, without question.

"I came very close myself," Kayneth mused. His first true mage battle and it had nearly ended everything. "The thought that I might have survived without my mage circuits…" Horrifying.

"You would still have had your limbs, master," Diarmuid pointed out and Kayneth had to fight back a hot retort. Didn't he understand?!

"I would much rather be a cripple than lose my magic," Kayneth said sharply and saw Diarmuid blink, his golden eyes widening. "And besides, I wouldn't have my arms and legs either. Do you know how integral mage circuits are?" No, of course he couldn't, Diarmuid wasn't a magus. "It would have burnt me out. If I'd survived at all it would have been as a husk."

"…Oh. I'm sorry, I didn't understand," Diarmuid said, a bit subdued. Then he sighed, looking down a bit. Kayneth swallowed, his momentary anger forgotten as he took in how beautiful Diarmuid looked, with that gentle cast of sadness on his face. "I've seen men survive battles with lost limbs before, or even worse. A broken back… we could only keep them alive and hope they would mend. Once in a while, they did, but it was rare."

"Yes, it would be," Kayneth murmured, feeling his fears rising up. "Would you think me a coward if I said I'm not sure I want to do this anymore?" Kayneth suddenly asked, wondering if Lancer would judge him for it. "My reasons for entering this were shallow and I fear my commitment is as well." Really, what had he been thinking? Did his family name really need any more luster? Diarmuid was frowning at him.

"Can you expand on that, my lord?" So ridiculously formal even in bed. He'd have to fix that, but later.

"Mmm… I entered this mostly to earn glory, more honor for my family name," Kayneth said but even as the words left his mouth they felt a little false. There was more to it than that. "I… craved the excitement. As my parent's only child and a powerful magus, I've been kept sheltered most of my life." Kayneth had sometimes been frustrated by that. He'd had a few idle thoughts of running away, when he was young, but he'd known he wouldn't get far. "And as a grown man, there was really nothing to use my skills on, no great challenges aside from research." Which Kayneth loved and yet… "When I realized a new holy grail war was beginning, it seemed a perfect time to finally use the skills I'd honed all my life. Something worthy of my attention…" Kayneth let his voice trail off, gazing up at the ceiling. Did he really want that anymore? He'd had a taste of danger and it had been bitter.

Then a hand gripped the back of his head and Kayneth was pulled out of his thoughts with a deep and extremely arousing kiss.

"I understand," Diarmuid murmured and Kayneth stared into his eyes, mesmerized by the warmth and compassion there. Warmth that quickly turned to heat as his servant kissed him again. Kayneth wanted to ask what Diarmuid thought he understood, precisely, but the thought was wiped out of his brain as Lancer pushed him down and mounted him. Did he mean to…?

Kayneth gasped as Diarmuid moved, grasping his penis and fluidly impaling himself onto it. God! Kayneth stared, entranced, as Diarmuid began to slowly move. Kayneth matched his rhythm, feeling that incredible tightness around his member. And that glorious, desirable man above him… reaching between them, Kayneth wrapped his hand around Lancer's length and began stroking him in time with their bodies.

"Oh yes, like that… my lord…" Diarmuid's voice was heavy with desire, his golden eyes half-closed. Kayneth gasped as he gazed raptly at the other man. Diarmuid was close to physical perfection but what truly captivated the magus was the true desire on his face, the pleasure he was taking in their coupling. Sola-Ui had never had sex with him but Kayneth couldn't imagine her reacting like this.

Kayneth speeded his strokes as they moved together faster, their bodies seeming to move in perfect unison. Sweat was beading on Lancer's skin and Kayneth could feel the fine droplets on his own body, proof of what they were doing. The heat in his loins was building, his orgasm coming closer and closer. Kayneth could feel Lancer's penis throbbing and knew he was close as well… hm… remembering something he particularly liked to do in the shower, Kayneth thumbed the tip and delicately played with the foreskin –

"AH!" Diarmuid arched, his head thrown back as he came in a rush of pleasure and semen. Kayneth cried out hoarsely as the wet heat around him tightened to an unholy degree, easily taking him over the edge as well.

When the pleasure finally ebbed they were left breathless, staring at each other. Diarmuid rested his palms on Kayneth's chest, panting softly. Kayneth though he'd never seen anything as radiantly beautiful than his servant was right now. Could this be love? It was… unlikely, to tell the truth. Diarmuid was the first man to come to his bed for no reason but lust and Kayneth knew he might be acting more on infatuation than real love. So might Diarmuid, for that matter, with his cursed love spot and hideous luck. Yet, Kayneth couldn't bring himself to care.

"What is your wish for the Grail?" Kayneth suddenly asked, realizing as he said the words that he couldn't imagine what it would be. Diarmuid smiled and it was incredibly sweet.

"I have no wish. Or rather, my wish has already been granted." Eh? "I just want to be alive, my lord. I loved my life so much and lost it too soon," Diarmuid said before gently disentangling their bodies. Kayneth swallowed, remembering the legends. Diarmuid had died far too young. "And more than anything, I want a lord who will not betray me." There was a sudden vulnerability in those golden eyes and Kayneth pulled him into a gentle kiss.

"Of course not," Kayneth murmured, considering something. He wasn't sure he wanted to continue with his place in the Grail War. If he was going to exit and still keep Lancer, though, that would take a lot of work. Hmm, he would have to look into that. And something to deal with the beauty spot too. Otherwise that would be a damned nuisance… Kayneth was vaguely aware of his own eyelids sagging and felt a warm hand go down his back.

"Sleep, master. You should be well rested for tomorrow," Diarmuid's voice was warm and despite his exhaustion, Kayneth felt his cock twitch. Vaguely he knew he should be plotting strategy tomorrow but he probably wouldn't.

His Servant was proving to be all too alluring.

* * *

Kayneth frowned at the plans spread over his workbench. The calculations were straightforward enough. They were also _obscene._ He could see why no one ever did this.

"It's feasible though," Kayneth muttered to himself. Supporting Diarmuid on nothing but his personal prana was possible, if just barely. His combat effectiveness would be cut down immensely though. He could start husbanding prana though, storing it in batteries. Hmm, efficiencies. Kayneth suddenly wondered how _efficient_ he could make his magic. Not something he'd ever considered before.

A warm hand gently touched the back of his neck and Kayneth sighed, leaning into it. Diarmuid took that as permission, which it was, and began gently kneading the tight muscles. Kayneth reflected that his servant was getting very good at timing his approach. He seemed to know when the magus was getting fed up and needed a distraction.

"What have you been working on, my lord?" Diarmuid asked curiously, glancing over his shoulder at the papers.

"Mmm… just some calculations." Kayneth didn't want to share it yet. It would be a very sweet surprise for Diarmuid. "I… oh god." Kayneth sighed as a very large moth flitted into the room. His mother would have very sharply told him it was a _butterfly_ , not a moth, but he'd decided as a child they were moths. "I should lock them out," Kayneth said gloomily. That would be foolish though. There was actually some important content, in between the diatribes and tearful remonstrations.

 _Kayneth, sweetie, please come home! This is all too dangerous!_ Well, that was a new tactic. Although he was sure – _We still love you even if you're… like that… please come home and we can arrange something, please!_ Cue the waterworks. What did his mother mean by 'arrange something' though? Kayneth gloomily reflected on it. Probably another arranged marriage, this time to someone less powerful but more biddable than Sola-Ui. Someone who needed support? Quite likely. Diarmuid's hand had gone still and Kayneth reached up to take it, giving him a gentle squeeze. _We miss you Kay-kay please come home!_ He really hated that nick-name.

"…That was actually the most effective message she's sent so far," Kayneth muttered. It made him feel a touch guilty and it played to his own fears.

"My lord, what will you do?" Diarmuid asked before clarifying. "I mean, after we have achieved the holy grail." A bit optimistic there, but it was his nature.

"I'm not sure. Go home and try to weather this firestorm," Kayneth said after a moment of thought. "The real thing I can't afford to lose is my position as a professor." Honestly, he treasured that. The thought of retiring to his estates to practice there didn't have nearly as much appeal. "It's not that I enjoy teaching, precisely, although I do…" Somewhat of a surprise really. "I need other people's thoughts bouncing off mine. Talking out problems really helps." Kayneth thought he would never have managed to make Volumen Hydrargyrum if he hadn't had other masters to talk to. Although he'd always been careful not to reveal the full extent of his work. It was a careful balance.

"I'm not sure why these things are forbidden in the first place," Diarmuid observed, gently placing an arm around him. Kayneth leaned back, feeling comforted by the strength of his Servant. "The priests say it goes against the natural law and God forbids it but… why?"

"Mmm, well, it goes against the whole 'be fruitful and multiply' part. And honestly, that's why we forbid it," Kayneth said gloomily. He wasn't out of his family obligations yet. "I'm going to have to get married you know." The arm around him gave a gentle squeeze.

"I do know, my lord. An only son always has great obligations," the note to his voice… Kayneth turned his head to look at Lancer. His brows were drawn together and his golden eyes were haunted with pain.

"Were you an only child?" Kayneth asked, trying to recall the legend. He honestly didn't think it mentioned if Diarmuid had siblings. There was a brief pause before his servant stirred.

"I was, but I should not have been," Diarmuid said and Kayneth decided not to ask. Just thinking about it was causing his servant pain. His thoughts, though, went another path.

"I've noticed that with the oldest heroes, the legends seem to tell us very little about you," Kayneth murmured. "They tell us what you did, but never anything about why." Although they could infer quite a bit. Although, even then, who knew if the depictions were accurate? "It's like the person gets lost, somewhere along the way." Lancer suddenly chuckled and Kayneth blinked.

"I should have committed my life to paper. But I fear no one would have read it," Diarmuid said cheerfully and Kayneth was glad to see he'd accidentally lightened the mood. "I know how it would have been… 'Went to the river to bathe. Three maidens hiding in the bushes to watch. Going back to the castle to bathe in a bucket again." Kayneth choked a little at the image.

"Did they really?!" From the pained yet amused look on Lancer's face, they really had. "That love curse is a bit – hm?" There was an odd tremor beneath his feet. "An earthquake?" Japan was prone to those. Kayneth pulled away from Diarmuid and picked up his sheets from the table, gently putting them together. There was a glass of water on the table and his work on the second part was particularly –

Then the world went completely insane.

" _KAYNETH!"_ Diarmuid grabbed him as the whole room seemed to flex. Kayneth hung onto the papers out of pure reflex, utterly shocked as the floor and ceiling did things that floors and ceilings should never, ever do. Vaguely he heard an ear-shattering _sound_ but then Lancer was carrying him, moving with the full agility of his class. Kayneth clung to him as they shot out through a window and stared, shocked, as the entire hotel crumbled to dust behind them. Well, not dust. More like a huge cloud of debris.

When they were safely away, Diarmuid slowed to a halt before gently setting him down. Kayneth blinked several times, trying to reboot his brain.

"I… what?" Well, that wasn't too coherent. Try again. "What just happened?" He was getting there. Diarmuid looked bewildered.

"I do not know my lord. Did you sense no magic?" Kayneth shook his head. There hadn't been anything magical about that. "What could it have been?"

"An attack on us but how…" Kayneth said before realizing he'd almost crushed the papers in his hands. Blinking at them he smoothed them out before folding them and putting them into his pockets. That small action seemed to steady him and helped him think. "Oh damnation, modern technology. Explosives in the basement?" Yes, it had to be that. But… "The complete disregard for life seems like Kiritsugu." Although he couldn't be absolutely sure. Yet, it did seem like the notorious Mage Killer. "Why didn't I think of this?!" But he knew why. Kayneth groaned, rubbing his forehead. "Blinding by my own preconceptions!" No magus would attack another magus this way. But Kiritsugu was the Mage Killer, he'd do anything to win.

"My lord, what should we do?" Diarmuid asked, a touch anxiously. Kayneth took a deep breath, steadying himself.

"We'll go to the secondary base." He had anticipated that they might need to move at some point. "It's not very nice," Kayneth warned and Diarmuid smiled, amused.

"I've stayed in holes in the ground before, my lord," he said and Kayneth couldn't help but laugh. "My lord?"

"It is a hole in the ground, literally. Fortunately it is furnished a bit." They wouldn't be totally lacking in comforts. "Well, let's get started." Kayneth had Volumen Hydrargyrum and Diarmuid. Overall, his power was still intact despite the setback. And he'd just been firmly reminded that the Grail War was still happening and he was still a participant.

As they began walking towards his secondary base, Kayneth resolved to devote his attentions to the contest. One way or another, he planned to survive.

* * *

A few days later.

 _I'm not happy about this, Lancer._

 _"_ It will be fine, Master." Diarmuid sounded entirely too sure of himself for Kayneth's peace of mind. "Saber would never violate the white flag of truce. It would be beyond dishonorable."

 _She isn't the one I'm worried about._ Kayneth replied irritably. He was speaking through Volumen Hydrargyrum, which he had shaped into a humanoid form and was now using as a kind of puppet. His physical body was safely ensconced in their hideaway. _Kiritsugu has no honor or respect for tradition._ The destruction of his fortress had made that clear to him. Really, explosives in the basement? What self-respecting magus did such a thing?

"I agree and that is why I shall meet them while you communicate through your mercury summoning." Diarmuid said easily and Kayneth was tempted to take a swipe at him but he restrained himself. It would be juvenile and unfitting of someone of his age and stature.

 _Your life does have meaning to me._ He said instead and Diarmuid's head turned to look at his mercury avatar. His impish smile and the warmth in his eyes threatened to turn Kayneth's knees to water.

"I appreciate your concern, My Lord. But I am your knight and it is my place to risk my life for you." He was tempted to argue but decided to save his breath. Lancer was hopelessly wedded to chivalry.

Then Kayneth sensed the aura of an approaching servant and his attention snapped to that. From the subtle tensing of Diarmuid's back, he felt it too.

They arrived soon after that and Kayneth tried to calm himself as he looked at Kiritsugu. The man inspired a combination of rage and fear that was deeply unsettling to him and unworthy of a powerful magus.

"Saber! It is a pleasure to see you again." And that was the voice of insanity. Kayneth closed his eyes for a moment in mental pain. Diarmuid sounded genuinely welcoming.

"It is my pleasure as well, although I cannot say the same for your master." Sabers tone was coolly courteous and she directed a look of flat dislike at the mercury figure. Kayneth felt honestly puzzled. "Hiding in shadows while sending a woman to do your dirty work, magus?"

"My lady?" Diarmuid said with blank incomprehension as Kiritsugu watched, slowly smoking a cigarette. Kayneth said nothing. It was better to stay silent than betray ignorance.

"You did not even mention it to your servant?" Her gaze at him was full of contempt. Kiritsugu spoke then, flicking away a bit of ash from his cigarette.

"Enough. I'm sure you know what we're here for, Kayneth." Not a clue. "But just to let you know she's still alive..." Kayneth blinked and he saw Diarmuid stiffen as a woman was forced out of the woods at gunpoint by another woman, this one all in black. She fell to her knees and they could see she was bound and gagged. Kayneth immediately understood what was going on.

 _Kiritsugu, I am making this offer to you in all due seriousness. If I pay you a thousand dollars will you shoot her?_ He asked and Sola-Ui's eyes widened as she made a protesting sound behind her gag.

"Master!" Diarmuid exclaimed as Saber and Kiritsugu both stared, taken aback.

 _What, too low? Ten thousand!_ Kayneth quipped, knowing his Servant would have a fit. Lancer did not disappoint.

"My Lord! You cannot let them murder a helpless woman, even if she's a vicious harpy!" Kayneth found that highly entertaining. Sola-Ui's outraged squeal was the best part.

 _Can't I? Don't you see what she was up to?_ Kayneth was sure he knew, in a general sense. _She meant to steal Saber so she could enter the game personally. We would have been her first target. Either she would have killed me and dropped Saber for you, or she would have found a way to force us into compliance._ He was sure Lancer was still Sola-Ui's primary objective. Would she use the Grail to make him love her? Ah, shades of Grainne. _Most likely by keeping me chained up and threatening to break my fingers unless you helped her._ He could absolutely see her doing it.

"I do not think she would really do that." Diarmuid protested and Kayneth felt a bit of pity for him. He was far too soft on women, in general. "Although she has done many unsettling things. Like the time she tried to ambush me in the shower." He did actually know about that, Lancer had reported it at the time. "And the… very odd dinner… and the time I think she tried to electrocute you…" That caught his attention.

 _What? I don't remember that!_ And an attempt on his life would certainly have been memorable. Kayneth was splitting his attention and saw that Sola-Ui was turning an interesting color and making plenty of noises behind her gag. As he watched, the woman behind her nudged her with the gun. Kiritsugu seemed fascinated by their interplay while Saber was staring, her mouth a little open. Diarmuid rubbed his chin before speaking reluctantly.

"That incident with the coffee pot. She apologized most prettily but I happened to see her face as she turned away from you. She… smirked, My Lord. It was deeply unsettling but as I believed you truly loved her, I did not want to say anything." Kayneth digested that for a moment. He'd honestly believed that had been an accident.

 _Thank you, I'll sleep a bit more uneasily knowing that. Anyway, as I'm sure you can infer, there has been a falling out._ He said to Kiritsugu. _Although, don't shoot her just yet._ This was giving him an idea. _Tell me, what exactly did you want from me?_ Kiritsugu blew a cloud of smoke before speaking slowly.

"I was planning to ask that you exit the game, with a geas on your family crest to seal it." Hmm, interesting. "I assume that will no longer work."

 _Don't throw it away just yet. Do you know why I entered this competition in the first place?_ He asked before answering himself. _To enhance my reputation. I wanted the glory and prestige of winning the Grail. That probably sounds a bit shallow._

"Not at all, my lord. Men have gone to war for glory many's the time." Diarmuid said loyally and Kayneth sighed.

 _But isn't it usually in their twenties? I'm a bit old for this._ But then, his twenties had been spent on his magecraft. Maybe the search for glory had just been delayed. _Anyway, the point I'm getting at is that this is no longer possible. Sola-Ui has already sent word back to the Clock Tower of my infidelity with my own Servant._ Diarmuid coughed and looked away at that. Was he blushing a bit? How cute. _So far I've gotten two messages from my father, three from my mother and one from Sola-Ui's father. Also, I'm being recalled from my position to face a full tribunal._ Kayneth summed up. Diarmuid looked a little pained as he remembered… he'd heard the content of those messages and they weren't nice. _My reputation is currently a radioactive waste heap._ And yet, he couldn't seem to care that much. _However, I could ransom Sola-Ui back to her father._ Not for money, but for his influence. And saving her from the notorious Mage Killer… yes, that would be worth something.

"You could use the Grail to repair your reputation." Saber observed and Kayneth blinked at the thought.

 _I don't think I could stomach using the ultimate power of the world for that._ He said after a moment. _I'd been planning to wish for something trite yet profound, like world peace._ Kiritsugu actually seemed surprised for a moment. Interesting. _What do you intend to wish for?_ Kayneth asked him bluntly and there was a pause before the Mage Killer responded.

"World peace." How ironic. And somehow, Kayneth could believe it. That surprised moment had been quite genuine. Had Kiritsugu seen too much death and now longed to do something positive with his life? Kayneth considered his options for a moment.

 _I have a proposal for you,_ Kayneth said, glancing at Lancer from the corner of his eye. The man was frowning and there was a distinct chilliness in his golden eyes. He'd have to make this up to him later. _Give me Sola-Ui and I will leave the game, with a seal on my family crest. And I'll take Sola-Ui back to the clock tower, delivering her to her father. However, after that her actions will be her own._ Kayneth wasn't going to take any responsibility for her beyond that. _And I want you to take an oath on your family crest that neither you nor any of your minions will interfere with me in any way._ Hard to see why he would but Kiritsugu might believe in clearing up loose ends.

"My lord, you can't!" Diarmuid suddenly exploded and Kayneth sighed to himself. This was going to be the hard part. "What about me? I'm only here because of the Grail and you know my wish!" And it was going to be fulfilled, although perhaps not for too long if they flamed out impressively enough. "What about _us?"_ Sola-Ui was making protesting sounds behind her gag as well, Kayneth noticed.

 _You are my Servant and you will obey me. I have decided I am no longer interested in pursuing this prize,_ Kayneth said sternly before deliberately invoking his seal. Lancer would forgive him later, when he understood what was behind it. _Diarmuid, by the power of my command seal I demand that you submit your will to mine and accept your fate,_ Kayneth said forcefully and saw pure betrayal on the man's face. Damnation, that was hard to see. And Saber saw it as well.

"You monster," Arturia whispered as Sola-Ui pitched a fit, as best she could. The woman behind her nudged her with the gun again. Kiritsugu just removed his cigarette from his mouth, blowing a bit of smoke before speaking.

"Acceptable. I have the scroll here. It will need some amending." Yes, no doubt. Kayneth deliberately ignored it as Diarmuid sank to his knees, lowering his head in despair. Saber stayed by Kiritsugu's side but from the look on her face, Kayneth knew she wanted to comfort her fellow servant. Well, this just had to be. And the expression on Sola-Ui's face was perfect.

After an amiable time dickering over the exact conditions of both seals, Kayneth used his mercury body to sign the scroll. Kiritsugu signed his own scroll and they shook hands, sealing the deal. Kayneth would have one day to officially exit the game, which was fine. He knew what he'd do and a day was plenty of time to do it in. The woman in black administered a drug to Sola-Ui via injection and then Kayneth reinforced it with a magical sleep. He'd turn that into a stasis when he got back to his hideaway. Hmm, he should likely take her back in a coffin, that would be easy enough.

 _To make things easier for you, I'll return to the Clock Tower via train. It will take a week._ It would also be easier to get the coffin onboard. _So assuming she takes a plane immediately, it will be a week and a day before Sola-Ui can get back here._ From the pace events were moving, Kayneth doubted Sola-Ui would make it in time.

"You are a dishonorable creature, magus, to so betray the trust placed in you," Saber said, her voice very cold. Kayneth glanced at Diarmuid and saw he hadn't moved an inch. "You will not be forgiven for this act."

 _Servants are tools, to be used and disposed of. Don't think for one moment your Master regards you otherwise,_ Kayneth returned coldly, fairly sure he spoke the truth about Kiritsugu. About himself? He was lying. Kayneth caught the movement from the corner of his eye and turned his head to see Diarmuid staring at him now. Such pain and deep hurt. Kayneth almost wished Lancer was angry with him, but the command seal he'd used likely prohibited it.

"Enough. Come, Saber," Kiritsugu said and they left, although Saber gave him a backward glance full of hate. Kayneth didn't care. In fact, Saber's hatred was a good thing. Everyone needed to believe he was truly the cold hearted, vicious magus he pretended to be.

 _Lancer, carry Sola-Ui for me,_ Kayneth instructed but Diarmuid just looked away. _Lancer!_

"Do it yourself, _my lord,_ " Diarmuid's tone was venomous and Kayneth sighed inside. He wasn't going to waste his final command seal on something so petty and he WAS using Volumen Hydrargyrum at the moment so it was hardly a difficulty. He picked up Sola-Ui and slung her over his shoulder. She felt weightless to his mercury summoning.

 _Come,_ Kayneth said and walked away, confident Diarmuid would have to follow. And he did, although slowly. What should he do to make this up to him? Cake might be involved. And sprinkles. Many, many sprinkles.

Mildly entertained by the mental image of a huge "I apologize" cake covered in sprinkles and chocolate – it would have to be chocolate, Diarmuid loved it – Kayneth gently set Sola-Ui down on a couch. Then he freed his awareness from Volumen Hydrargyrum and shook himself, blinking.

"Ugh," Kayneth muttered, steadying himself. What an odd feeling. Then he reached for the bottle and put his toy back. Kayneth wondered what else he could do with it. His battle with Kiritsugu had made it clear the mercury had some limitations.

Saving that for later, Kayneth sealed the bottle and turned to his Servant. Diarmuid wasn't looking at him, just staring at the wall. Kayneth moved to his side and grasped his chin, forcing his servant to look at him. Diarmuid's hand moved to knock his away, but Kayneth narrowed his eyes.

"I ordered you to submit to my will," he reminded the Servant and Diarmuid shuddered slightly before dropping his hand. Gold eyes dulled with resignation and pain. "And my will is…" Kayneth kissed Diarmuid, passionately, and felt the man stiffen in surprise. "That you will remain by my side as my trusted servant, for as long as I might live," Kayneth breathed in Lancer's ear and heard a sharp indrawn breath.

"My lord?!" Diarmuid pulled away from him and this time, Kayneth let him. His expression was shocked, his golden eyes wide. "What… you can't…"

"Yes, I can," Kayneth said, reflecting on it. Waver believed you could improve your prana pool through study and effort but it just wasn't true. His own prana pool was as large as it had been at sixteen… and that was obscenely large. "The grail has done the work of summoning you. It will require an immense sacrifice of energy to the grail and then a high, permanent drain, but I can maintain you as a familiar." He'd already done the calculations. Diarmuid's eyes were, if anything, a bit wider. "Mind you, my combat effectiveness will be cut down by roughly two thirds, perhaps even as much as three quarters. And the timing is absolutely horrible. So you might not enjoy your life for too – MPH!" Kayneth was NOT expecting Lancer to suddenly lose his mind and hug him. And while that might have been nice, it wasn't when he appeared to be using his full strength. He tried to tell the man that, but he wasn't listening.

"Thank you my lord, thank you, I couldn't bear to be betrayed again thank you thank you – OW!" Diarmuid jerked away as Kayneth lost his patience and bit him. "My lord?!"

"Idiot, I couldn't breathe!" Kayneth snapped, still a bit breathless. He straightened his clothing, shaking his head as Diarmuid smiled sheepishly. "Don't be stupid or I might change my mind," he growled and they both knew it was false. Diarmuid's smile widened.

"I understand now. You wanted to convince Sola-Ui I am dead." Yes indeed. That was the only way to free her mind from the spell of the beauty mark. "But… my lord? Will she not see me in the Clock Tower?" Diarmuid asked and Kayneth nodded. That brought him to the other part of his plan.

"I plan to place a spell on you, a modified version of the Curse of Echo." Diarmuid looked confused so Kayneth explained. "The magic of your beauty spot is a divine curse and cannot be lifted. But another curse can be layered onto it. The Curse of Echo is a truly fearsome curse… it turns the bearer into a living ghost. They can be heard and briefly acknowledged, but not remembered past the moment." Diarmuid swallowed. Well, it was a daunting curse. "It's a difficult spell but I'm confident I can do it… but as I said, modified. It will only affect women. They'll see you, fall in love with you and promptly forget you." Kayneth ran a hand through his hair, thinking about the modifications. He'd been working on the curse since he first considered this idea. "Men will see you as you are and you'll be my new manservant and familiar." If Diarmuid had to protect him, which was likely, word would soon get around that his manservant was far more. Kayneth planned to do his best to obfuscate exactly what Lancer was, though.

"A clever plan and one that gladdens my heart. I've enjoyed the company of women but this beauty spot is such a horrible curse," Diarmuid said with a small grimace and Kayneth nodded. "And I will remain alive." He seemed so radiant when he said that. Kayneth couldn't help but smile.

"Just try to keep me alive. We're both going to be in hot water at the Clock Tower," Kayneth said, amused as Diarmuid seemed even happier. He was looking forward to mayhem, the idiot.

"I will do my best for you, my lord," his Servant and lover said cheerfully and Kayneth chuckled softly before sobering.

"I need to begin the rituals to free you from the Grail system while keeping you corporeal. We have exactly a day." Kayneth warned and Diarmuid nodded, still smiling. "Over here…" Soon Kayneth was deeply immersed in his craft, feeling the power flowing through his fingers. It was uplifting although he knew, when he finished, that he would never feel it at this level again.

It was worth it to keep Diarmuid by his side.


End file.
